Magnetically-Coupled Cantilevers with Antiphase Bistable Behavior for Kinetic Energy Harvesting

This work deals with bistable devices for vibration energy harvesting. We have addressed this subject through MEMS cantilevers and the use of two facing magnets, with opposed magnetization, in order to obtain the desired double-well potential energy function. However the fabrication on MEMS devices of micromagnets placed very close one each other and having non-parallel magnetization is seriously challenging: parallel magnetization would be greatly preferable. Based on this latter consideration, new device architecture is presented here: two parallel cantilevers, with a magnet on each tip, are used. The two magnets are equally oriented and therefore provide repulsive forces that in turn induce antisymmetric bistable behaviors in the two cantilevers. The system has been analytically modeled and an experimental prototype has been realized and tested obtaining very promising results. (C) 2012 Elsevier Ltd....Selection and/or peer-review under responsibility of the Symposium Cracoviense Sp. z.o.o.